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-rw-r--r--include/linux/blk-cgroup.h461
1 files changed, 5 insertions, 456 deletions
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index b4de2010fba5..f2ad8ed8f777 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -25,14 +25,8 @@
#include <linux/kthread.h>
#include <linux/fs.h>
-/* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */
-#define BLKG_STAT_CPU_BATCH (INT_MAX / 2)
-
-/* Max limits for throttle policy */
-#define THROTL_IOPS_MAX UINT_MAX
#define FC_APPID_LEN 129
-
#ifdef CONFIG_BLK_CGROUP
enum blkg_iostat_type {
@@ -44,6 +38,7 @@ enum blkg_iostat_type {
};
struct blkcg_gq;
+struct blkg_policy_data;
struct blkcg {
struct cgroup_subsys_state css;
@@ -76,36 +71,6 @@ struct blkg_iostat_set {
struct blkg_iostat last;
};
-/*
- * A blkcg_gq (blkg) is association between a block cgroup (blkcg) and a
- * request_queue (q). This is used by blkcg policies which need to track
- * information per blkcg - q pair.
- *
- * There can be multiple active blkcg policies and each blkg:policy pair is
- * represented by a blkg_policy_data which is allocated and freed by each
- * policy's pd_alloc/free_fn() methods. A policy can allocate private data
- * area by allocating larger data structure which embeds blkg_policy_data
- * at the beginning.
- */
-struct blkg_policy_data {
- /* the blkg and policy id this per-policy data belongs to */
- struct blkcg_gq *blkg;
- int plid;
-};
-
-/*
- * Policies that need to keep per-blkcg data which is independent from any
- * request_queue associated to it should implement cpd_alloc/free_fn()
- * methods. A policy can allocate private data area by allocating larger
- * data structure which embeds blkcg_policy_data at the beginning.
- * cpd_init() is invoked to let each policy handle per-blkcg data.
- */
-struct blkcg_policy_data {
- /* the blkcg and policy id this per-policy data belongs to */
- struct blkcg *blkcg;
- int plid;
-};
-
/* association between a blk cgroup and a request queue */
struct blkcg_gq {
/* Pointer to the associated request_queue */
@@ -141,93 +106,11 @@ struct blkcg_gq {
struct rcu_head rcu_head;
};
-typedef struct blkcg_policy_data *(blkcg_pol_alloc_cpd_fn)(gfp_t gfp);
-typedef void (blkcg_pol_init_cpd_fn)(struct blkcg_policy_data *cpd);
-typedef void (blkcg_pol_free_cpd_fn)(struct blkcg_policy_data *cpd);
-typedef void (blkcg_pol_bind_cpd_fn)(struct blkcg_policy_data *cpd);
-typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp,
- struct request_queue *q, struct blkcg *blkcg);
-typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd);
-typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd);
-typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd);
-typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd);
-typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd);
-typedef bool (blkcg_pol_stat_pd_fn)(struct blkg_policy_data *pd,
- struct seq_file *s);
-
-struct blkcg_policy {
- int plid;
- /* cgroup files for the policy */
- struct cftype *dfl_cftypes;
- struct cftype *legacy_cftypes;
-
- /* operations */
- blkcg_pol_alloc_cpd_fn *cpd_alloc_fn;
- blkcg_pol_init_cpd_fn *cpd_init_fn;
- blkcg_pol_free_cpd_fn *cpd_free_fn;
- blkcg_pol_bind_cpd_fn *cpd_bind_fn;
-
- blkcg_pol_alloc_pd_fn *pd_alloc_fn;
- blkcg_pol_init_pd_fn *pd_init_fn;
- blkcg_pol_online_pd_fn *pd_online_fn;
- blkcg_pol_offline_pd_fn *pd_offline_fn;
- blkcg_pol_free_pd_fn *pd_free_fn;
- blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn;
- blkcg_pol_stat_pd_fn *pd_stat_fn;
-};
-
-extern struct blkcg blkcg_root;
extern struct cgroup_subsys_state * const blkcg_root_css;
-extern bool blkcg_debug_stats;
-
-struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg,
- struct request_queue *q, bool update_hint);
-int blkcg_init_queue(struct request_queue *q);
-void blkcg_exit_queue(struct request_queue *q);
-
-/* Blkio controller policy registration */
-int blkcg_policy_register(struct blkcg_policy *pol);
-void blkcg_policy_unregister(struct blkcg_policy *pol);
-int blkcg_activate_policy(struct request_queue *q,
- const struct blkcg_policy *pol);
-void blkcg_deactivate_policy(struct request_queue *q,
- const struct blkcg_policy *pol);
-
-const char *blkg_dev_name(struct blkcg_gq *blkg);
-void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
- u64 (*prfill)(struct seq_file *,
- struct blkg_policy_data *, int),
- const struct blkcg_policy *pol, int data,
- bool show_total);
-u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v);
-
-struct blkg_conf_ctx {
- struct block_device *bdev;
- struct blkcg_gq *blkg;
- char *body;
-};
-
-struct block_device *blkcg_conf_open_bdev(char **inputp);
-int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
- char *input, struct blkg_conf_ctx *ctx);
-void blkg_conf_finish(struct blkg_conf_ctx *ctx);
-/**
- * blkcg_css - find the current css
- *
- * Find the css associated with either the kthread or the current task.
- * This may return a dying css, so it is up to the caller to use tryget logic
- * to confirm it is alive and well.
- */
-static inline struct cgroup_subsys_state *blkcg_css(void)
-{
- struct cgroup_subsys_state *css;
-
- css = kthread_blkcg();
- if (css)
- return css;
- return task_css(current, io_cgrp_id);
-}
+void blkcg_destroy_blkgs(struct blkcg *blkcg);
+void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay);
+void blkcg_maybe_throttle_current(void);
static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css)
{
@@ -235,27 +118,6 @@ static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css)
}
/**
- * __bio_blkcg - internal, inconsistent version to get blkcg
- *
- * DO NOT USE.
- * This function is inconsistent and consequently is dangerous to use. The
- * first part of the function returns a blkcg where a reference is owned by the
- * bio. This means it does not need to be rcu protected as it cannot go away
- * with the bio owning a reference to it. However, the latter potentially gets
- * it from task_css(). This can race against task migration and the cgroup
- * dying. It is also semantically different as it must be called rcu protected
- * and is susceptible to failure when trying to get a reference to it.
- * Therefore, it is not ok to assume that *_get() will always succeed on the
- * blkcg returned here.
- */
-static inline struct blkcg *__bio_blkcg(struct bio *bio)
-{
- if (bio && bio->bi_blkg)
- return bio->bi_blkg->blkcg;
- return css_to_blkcg(blkcg_css());
-}
-
-/**
* bio_blkcg - grab the blkcg associated with a bio
* @bio: target bio
*
@@ -291,22 +153,6 @@ static inline bool blk_cgroup_congested(void)
}
/**
- * bio_issue_as_root_blkg - see if this bio needs to be issued as root blkg
- * @return: true if this bio needs to be submitted with the root blkg context.
- *
- * In order to avoid priority inversions we sometimes need to issue a bio as if
- * it were attached to the root blkg, and then backcharge to the actual owning
- * blkg. The idea is we do bio_blkcg() to look up the actual context for the
- * bio and attach the appropriate blkg to the bio. Then we call this helper and
- * if it is true run with the root blkg for that queue and then do any
- * backcharging to the originating cgroup once the io is complete.
- */
-static inline bool bio_issue_as_root_blkg(struct bio *bio)
-{
- return (bio->bi_opf & (REQ_META | REQ_SWAP)) != 0;
-}
-
-/**
* blkcg_parent - get the parent of a blkcg
* @blkcg: blkcg of interest
*
@@ -318,96 +164,6 @@ static inline struct blkcg *blkcg_parent(struct blkcg *blkcg)
}
/**
- * __blkg_lookup - internal version of blkg_lookup()
- * @blkcg: blkcg of interest
- * @q: request_queue of interest
- * @update_hint: whether to update lookup hint with the result or not
- *
- * This is internal version and shouldn't be used by policy
- * implementations. Looks up blkgs for the @blkcg - @q pair regardless of
- * @q's bypass state. If @update_hint is %true, the caller should be
- * holding @q->queue_lock and lookup hint is updated on success.
- */
-static inline struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg,
- struct request_queue *q,
- bool update_hint)
-{
- struct blkcg_gq *blkg;
-
- if (blkcg == &blkcg_root)
- return q->root_blkg;
-
- blkg = rcu_dereference(blkcg->blkg_hint);
- if (blkg && blkg->q == q)
- return blkg;
-
- return blkg_lookup_slowpath(blkcg, q, update_hint);
-}
-
-/**
- * blkg_lookup - lookup blkg for the specified blkcg - q pair
- * @blkcg: blkcg of interest
- * @q: request_queue of interest
- *
- * Lookup blkg for the @blkcg - @q pair. This function should be called
- * under RCU read lock.
- */
-static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
- struct request_queue *q)
-{
- WARN_ON_ONCE(!rcu_read_lock_held());
- return __blkg_lookup(blkcg, q, false);
-}
-
-/**
- * blk_queue_root_blkg - return blkg for the (blkcg_root, @q) pair
- * @q: request_queue of interest
- *
- * Lookup blkg for @q at the root level. See also blkg_lookup().
- */
-static inline struct blkcg_gq *blk_queue_root_blkg(struct request_queue *q)
-{
- return q->root_blkg;
-}
-
-/**
- * blkg_to_pdata - get policy private data
- * @blkg: blkg of interest
- * @pol: policy of interest
- *
- * Return pointer to private data associated with the @blkg-@pol pair.
- */
-static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
- struct blkcg_policy *pol)
-{
- return blkg ? blkg->pd[pol->plid] : NULL;
-}
-
-static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg,
- struct blkcg_policy *pol)
-{
- return blkcg ? blkcg->cpd[pol->plid] : NULL;
-}
-
-/**
- * pdata_to_blkg - get blkg associated with policy private data
- * @pd: policy private data of interest
- *
- * @pd is policy private data. Determine the blkg it's associated with.
- */
-static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd)
-{
- return pd ? pd->blkg : NULL;
-}
-
-static inline struct blkcg *cpd_to_blkcg(struct blkcg_policy_data *cpd)
-{
- return cpd ? cpd->blkcg : NULL;
-}
-
-extern void blkcg_destroy_blkgs(struct blkcg *blkcg);
-
-/**
* blkcg_pin_online - pin online state
* @blkcg: blkcg of interest
*
@@ -439,231 +195,24 @@ static inline void blkcg_unpin_online(struct blkcg *blkcg)
} while (blkcg);
}
-/**
- * blkg_path - format cgroup path of blkg
- * @blkg: blkg of interest
- * @buf: target buffer
- * @buflen: target buffer length
- *
- * Format the path of the cgroup of @blkg into @buf.
- */
-static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen)
-{
- return cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
-}
-
-/**
- * blkg_get - get a blkg reference
- * @blkg: blkg to get
- *
- * The caller should be holding an existing reference.
- */
-static inline void blkg_get(struct blkcg_gq *blkg)
-{
- percpu_ref_get(&blkg->refcnt);
-}
-
-/**
- * blkg_tryget - try and get a blkg reference
- * @blkg: blkg to get
- *
- * This is for use when doing an RCU lookup of the blkg. We may be in the midst
- * of freeing this blkg, so we can only use it if the refcnt is not zero.
- */
-static inline bool blkg_tryget(struct blkcg_gq *blkg)
-{
- return blkg && percpu_ref_tryget(&blkg->refcnt);
-}
-
-/**
- * blkg_put - put a blkg reference
- * @blkg: blkg to put
- */
-static inline void blkg_put(struct blkcg_gq *blkg)
-{
- percpu_ref_put(&blkg->refcnt);
-}
-
-/**
- * blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants
- * @d_blkg: loop cursor pointing to the current descendant
- * @pos_css: used for iteration
- * @p_blkg: target blkg to walk descendants of
- *
- * Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU
- * read locked. If called under either blkcg or queue lock, the iteration
- * is guaranteed to include all and only online blkgs. The caller may
- * update @pos_css by calling css_rightmost_descendant() to skip subtree.
- * @p_blkg is included in the iteration and the first node to be visited.
- */
-#define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg) \
- css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css) \
- if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \
- (p_blkg)->q, false)))
-
-/**
- * blkg_for_each_descendant_post - post-order walk of a blkg's descendants
- * @d_blkg: loop cursor pointing to the current descendant
- * @pos_css: used for iteration
- * @p_blkg: target blkg to walk descendants of
- *
- * Similar to blkg_for_each_descendant_pre() but performs post-order
- * traversal instead. Synchronization rules are the same. @p_blkg is
- * included in the iteration and the last node to be visited.
- */
-#define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg) \
- css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css) \
- if (((d_blkg) = __blkg_lookup(css_to_blkcg(pos_css), \
- (p_blkg)->q, false)))
-
-bool __blkcg_punt_bio_submit(struct bio *bio);
-
-static inline bool blkcg_punt_bio_submit(struct bio *bio)
-{
- if (bio->bi_opf & REQ_CGROUP_PUNT)
- return __blkcg_punt_bio_submit(bio);
- else
- return false;
-}
-
-static inline void blkcg_bio_issue_init(struct bio *bio)
-{
- bio_issue_init(&bio->bi_issue, bio_sectors(bio));
-}
-
-static inline void blkcg_use_delay(struct blkcg_gq *blkg)
-{
- if (WARN_ON_ONCE(atomic_read(&blkg->use_delay) < 0))
- return;
- if (atomic_add_return(1, &blkg->use_delay) == 1)
- atomic_inc(&blkg->blkcg->css.cgroup->congestion_count);
-}
-
-static inline int blkcg_unuse_delay(struct blkcg_gq *blkg)
-{
- int old = atomic_read(&blkg->use_delay);
-
- if (WARN_ON_ONCE(old < 0))
- return 0;
- if (old == 0)
- return 0;
-
- /*
- * We do this song and dance because we can race with somebody else
- * adding or removing delay. If we just did an atomic_dec we'd end up
- * negative and we'd already be in trouble. We need to subtract 1 and
- * then check to see if we were the last delay so we can drop the
- * congestion count on the cgroup.
- */
- while (old) {
- int cur = atomic_cmpxchg(&blkg->use_delay, old, old - 1);
- if (cur == old)
- break;
- old = cur;
- }
-
- if (old == 0)
- return 0;
- if (old == 1)
- atomic_dec(&blkg->blkcg->css.cgroup->congestion_count);
- return 1;
-}
-
-/**
- * blkcg_set_delay - Enable allocator delay mechanism with the specified delay amount
- * @blkg: target blkg
- * @delay: delay duration in nsecs
- *
- * When enabled with this function, the delay is not decayed and must be
- * explicitly cleared with blkcg_clear_delay(). Must not be mixed with
- * blkcg_[un]use_delay() and blkcg_add_delay() usages.
- */
-static inline void blkcg_set_delay(struct blkcg_gq *blkg, u64 delay)
-{
- int old = atomic_read(&blkg->use_delay);
-
- /* We only want 1 person setting the congestion count for this blkg. */
- if (!old && atomic_cmpxchg(&blkg->use_delay, old, -1) == old)
- atomic_inc(&blkg->blkcg->css.cgroup->congestion_count);
-
- atomic64_set(&blkg->delay_nsec, delay);
-}
-
-/**
- * blkcg_clear_delay - Disable allocator delay mechanism
- * @blkg: target blkg
- *
- * Disable use_delay mechanism. See blkcg_set_delay().
- */
-static inline void blkcg_clear_delay(struct blkcg_gq *blkg)
-{
- int old = atomic_read(&blkg->use_delay);
-
- /* We only want 1 person clearing the congestion count for this blkg. */
- if (old && atomic_cmpxchg(&blkg->use_delay, old, 0) == old)
- atomic_dec(&blkg->blkcg->css.cgroup->congestion_count);
-}
-
-void blk_cgroup_bio_start(struct bio *bio);
-void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta);
-void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay);
-void blkcg_maybe_throttle_current(void);
#else /* CONFIG_BLK_CGROUP */
struct blkcg {
};
-struct blkg_policy_data {
-};
-
-struct blkcg_policy_data {
-};
-
struct blkcg_gq {
};
-struct blkcg_policy {
-};
-
#define blkcg_root_css ((struct cgroup_subsys_state *)ERR_PTR(-EINVAL))
static inline void blkcg_maybe_throttle_current(void) { }
static inline bool blk_cgroup_congested(void) { return false; }
#ifdef CONFIG_BLOCK
-
static inline void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay) { }
-
-static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; }
-static inline struct blkcg_gq *blk_queue_root_blkg(struct request_queue *q)
-{ return NULL; }
-static inline int blkcg_init_queue(struct request_queue *q) { return 0; }
-static inline void blkcg_exit_queue(struct request_queue *q) { }
-static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; }
-static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { }
-static inline int blkcg_activate_policy(struct request_queue *q,
- const struct blkcg_policy *pol) { return 0; }
-static inline void blkcg_deactivate_policy(struct request_queue *q,
- const struct blkcg_policy *pol) { }
-
-static inline struct blkcg *__bio_blkcg(struct bio *bio) { return NULL; }
static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; }
+#endif /* CONFIG_BLOCK */
-static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
- struct blkcg_policy *pol) { return NULL; }
-static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; }
-static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; }
-static inline void blkg_get(struct blkcg_gq *blkg) { }
-static inline void blkg_put(struct blkcg_gq *blkg) { }
-
-static inline bool blkcg_punt_bio_submit(struct bio *bio) { return false; }
-static inline void blkcg_bio_issue_init(struct bio *bio) { }
-static inline void blk_cgroup_bio_start(struct bio *bio) { }
-
-#define blk_queue_for_each_rl(rl, q) \
- for ((rl) = &(q)->root_rl; (rl); (rl) = NULL)
-
-#endif /* CONFIG_BLOCK */
#endif /* CONFIG_BLK_CGROUP */
#ifdef CONFIG_BLK_CGROUP_FC_APPID